Fuel cells, especially proton exchange membrane fuel cells (PEMFC) are known to generally comprise a number of component layers that provide electrical contact (electrodes); channels for coolant, fuel, and oxidant; diffusion layers for dispersing the fuel and oxidant; a catalytic element for each pole; and the electrolyte membrane.
In the manufacture of such fuel cells, consideration of the cost of fabricating and assembling multiple components and the ohmic losses across interfaces would appear to encourage the combination of functions. Yet the components described above are currently produced as discrete elements that require assembly into a unit stack. Moreover, one of the most costly components is the bipolar plate, which is currently machined from graphite.
For further background information, please refer to the following publications:
1. Stinton, et al., U.S. Pat. No. 5,075,160, Dec. 24, 1991. PA1 2. Lackey, et al., U.S. Pat. No. 4,580,524, Apr. 8, 1986. PA1 3. K. Kinoshita, F. R. McLamon, and E. J. Cairns, Fuel Cells: A Handbook, DOE/METC-88/6096, pp. 2-4, Lawrence Berkeley Laboratory, Berkeley, Calif., May, 1988. PA1 4. R. Lemons, J. Eberhardt, A. Landgrebe, D. MacArthur, R. Savenell, S. Swathirajan, D. Wilson, and M. Wilson, "Batteries and Fuel Cells," Current Status, Research Needs, and Opportunities in Applications of Surface Processing to Transportation and Utilities Technologies: Proceedings of a December 1991 Workshop, A. W. Czanderna and A. R. Landgrebe, Editors, NREL/CP-412-5007, pp. 21-1-21-14, National Renewable Energy Laboratory, Golden, Colo. September 1992. PA1 5. M. C. Kimble and N. E. Vanderborgh, "Reactant Gas Flow Fields in Advanced PEM Fuel Cell Designs," Proceedings of the 27th Intersociety Energy Conversion Engineering Conference, Vol. 3, pp. 3.413-3417, Society of Automotive Engineers, Warrendale, Pa. (1992). PA1 6. K. Strasser, "PEM Fuel Cells for Energy Storage Systems," pp. 630-635, Proceedings of the 26th Intersociety Energy Conversion Engineering Conference, Vol. 3, American Nuclear Society, La Grange Park, Ill. (1991).